This invention relates to an improved plaque board and a process for constructing the same and other wooden articles, including such furniture items as tabletops, desktops and the like.
In making various types of articles of a good quality wood such as walnut, the presently existing practice is to cut the wood into strips, provide suitable joints in the strips, and glue the strips together at the joints with the grain reversed in each adjacent strip to achieve the desired appearance. Aside from the obvious cost, time consumption, and workage problems associated with this procedure, the unsightly joints or seams detract from the appearance of the finished article, as does the color variation between the different strips. Also, the cost of an article formed of solid walnut is considerable and its heavy weight creates a problem in certan situations. Walnut and other woods expand and contract due to changes in the moisture content of the air, and a solid wooden article will thus frequently become warped considerably as a result of humidity variations.
Furthermore, a significant quantity of expensive wood is wasted during the construction of many solid wooden articles. For example, when it is desired to make a solid walnut plaque board having a somewhat irregular shape, a square or rectangular piece of solid walnut is cut away at the corners to form the desired shape. The portions of the wood that are cut away are of little utility so they are usually discarded. A similar waste problem exists when a knot or other imperfection must be cut from a solid piece and the relatively large quantity of wood surrounding the imperfection must be thrown away. Sapwood and other soft or inferior portions of the lumber cannot be used because of their appearance and undesirable characteristics.
Although attempts have been made to cover a core of inferior wood with good quality veneer, the results have been unsatisfactory for many of the reasons previously set forth. Additionally, the veneer does not adhere properly to the poor quality wood that forms the core of the article and it eventually peels therefrom, particularly during humidity changes which tend to warp the wood. The problem of adequately securing the veneer to a wooden core is further compounded by the tendency of the veneer to wrinkle due to its extreme thinness. Known processes of securing veneer to a core are inadequate to remove wrinkles from the veneer or resist further wrinkling, and the resulting unsightliness of the veneer and its tendency to peel from the core have presented a serious difficulty.
In view of the afore-mentioned problems, it is the primary goal of the present invention to provide an improved plaque board and method for constructing same, as well as other furniture items and like articles.
More specifically, an object of this invention is to provide a plaque board having an improved appearance. This feature is achieved by forming the opposite sides from thin, high quality veneer which has no joints or seams and which has a better and more consistent color than a solid board comprised of separate strips.
Another object of the invention is to provide a plaque board of the character described that is formed from inexpensive material. Since the bulk of the plaque board consists of a relatively inexpensive core material, only a small amount of high grade wood is required and the cost is thereby substantially reduced. In conjunction with the preceding, it is significant that a limited natural resource is conserved due to the reduced quantity of hardwood required to construct the plaque board.
Yet another object of the invention is to provide a plaque board of the character described that is light in weight yet is of sturdy construction. The provision of a light weight core results in a considerably reduced overall weight compared to that of solid wood, while the rigid core gives the plaque board the strength of a solid member.
A further object of the invention is to provide a plaque board of the character described that is not susceptible to warping or deformation due to humidity variations. The polyurethane core, which is not sensitive to moisture, is bonded to the veneer and frame to provide an integral member which retains its shape and strength during humidity changes.
A still further object of the invention is to provide a novel process for economically constructing a high quality wooden article. Articles such as plaque boards and the like may be quickly and easily manufactured with a minimum amount of equipment since the cumbersome and time consuming process normally associated with making solid wooden articles is eliminated. A significant feature of the invention is that the waste problem previously set forth is reduced considerably because of the small amount of wood required to construct the article. It is a further significant feature of the construction process disclosed herein that the veneer is moistened by the polyurethane foam and any wrinkles or other irregularities in the veneer panels are removed by pressing the panels inwardly as the foam expands outwardly against their inward surfaces.
Other and further objects of the invention together with the features of novelty appurtenant thereto will appear in the course of the following description.